Psychology and neuroscience Dr. Andrew Young Behavioural Neuroscience Group PS1009 Applied Psychology

PS1009 Psychology and brain function As psychologists we study the interaction between an organism and its environment Perceiving the environment (sensory perception) Behavioural responses Integration Decision Transmission The Brain Neurones Chemicals (Neurotransmitters) Neuronal connectivity Electrical activity

PS1009 Brain function and behaviour Paul Broca (c1860) Studied a patient called ‘Leborgne’ intelligent and capable of comprehending spoken and written language but unable to speak more than a very few meaningless syllables for 21 years capable of communication using motor gestures Post-mortem study of brain showed: single lesion towards back of left frontal lobe first evidence for highly localised control of function in the cortex

PS1009 Types of measurement Post-mortem studies Provides anatomical information Of limited value for functional studies Living neurones in isolation (in vitro - e.g. cultures, slices) Show how living neurones can function But give limited information on behaviour Studies intact brains Effects of brain injury on behaviour Effects of drugs with known pharmacology on behaviour Monitoring brain activity during behaviour Underpinned by post-mortem and in vitro studies

PS1009 Study of normal brain function Perception – vision, sight, smell, taste Movement Language Learning and memory Sleep Pain and analgesia Mood Personality ….. many more Neuronal systems involved – e.g. hippocampus Electrical process involved – e.g. LTP Neurotransmitters involved – e.g. glutamate (* see PS1003 lectures) * * * * *

PS1009 Study of abnormal function Studying neuronal processes and/or neurotransmitters involved in Perceptual disorders Motor disorders Schizophrenia Depression Anxiety Parkinson’s disease Ischaemia (stroke) Epilepsy Addiction ….. many others

PS1009 Symptoms of psychosis Abnormal ideas : delusions (mood, persecution, grandiose, hypochondriacal) Abnormal perceptions : hallucinations (mainly auditory) Formal thought disorder : derailment, loss of goal, neologisms, poverty of speech content Motor, volition and behavioural disorder : catatonia, abnormal posture, avolition, mutism, Emotional disorders : affective flattening, emotional withdrawal, anhedonia. Difficult to measure objectively

PS1009 Can psychology help us understand schizophrenia? Understanding biological basis of psychological function - relationship with dysfunction in psychiatric disease effects of brain injury on behaviour effects of drugs on behaviour pharmacology of drugs with therapeutic effects studies with tasks which rely certain brain areas brain imaging studies, especially function in these tasks use of animal models of psychological function

PS1009 Effects of brain injury on behaviour Temporal lobe dysfunction (e.g. temporal lobe epilepsy) Can lead to some symptoms similar to positive symptoms of schizophrenia. Frontal lobe damage (e.g.frontal lobectomy) Leads to symptoms similar to negative symptoms of schizophrenia.

PS1009 Effects of drugs on behaviour Several drugs known to cause symptoms similar to schizophrenia: Amphetamine – causes hallucinations and delusions very similar to positive symptoms of schizophrenia Are positive symptoms associated with increased dopamine? LSD – causes hallucinations which are similar the positive symptoms of schizophrenia Are positive symptoms associated with increased serotonin?

PS1009 Pharmacology of drugs with therapeutic effect Classical (‘typical’) antipsychotic drugs Antagonists at dopamine receptors Newer (‘atypical’) antipsychotic drugs Antagonists at both dopamine and serotonin receptors Dopamine and serotonin over-activity both implicated in schizophrenia.

PS1009 Studies using tasks relying on certain brain areas Positively symptomatic schizophrenics are deficient in tasks requiring temporal lobe function e.g. selective attention – latent inhibition (learning to ignore irrelevant stimuli) Schizophrenics are deficient in tasks requiring frontal lobe function e.g. Wisconsin card sort, Tower of Hanoi First degree relatives of schizophrenics are also deficient in frontal lobe tasks.

PS1009 Brain imaging studies Functional magnetic resonance imaging (fMRI) studies have looked at brain areas activated during these tasks: e.g. Latent inhibition How does this differ in schizophrenic patients? Z-coordinate of slice Left Right Young AMJ et al., 2005

PS1009 Animal models of psychological function Latent inhibition in animals – relationship with schizophrenia Poor Good Learning LI SALINE AMPH AMPH +HAL NON-PREEXPOSED PREEXPOSED Schizophrenia Latent inhibition provides a model for studying the neural basis of schizophrenia

PS1009 Information processing deficits in schizophrenia These may be indicative of deficits in sensory gating (e.g. selective attention). Kraepelin (1913) "Schizophrenic patients are unable to exclude irrelevant sensory information from their awareness" McGhie & Chapman (1961) Pateint A : "I can't shut things out" Patient B : "I let all the sounds come in that are there" Patient C : "I'm attending to everything at once, so I don't really attend to anything"

PS1009 Psychology and neuroscience Understanding the neural and neurochemical basis of psychological function in the normal brain Perception Intrinsic processing Motor output ‘Behaviour’ Studying the neural and neurochemical basis of behaviour gives us insights into dysfunctions underlying psychiatric disease.